1. Field of the Invention
The present invention relates to an encoding and decoding apparatus for encoding and decoding standard video signals and high definition video signals.
2. Description of the Related Arts
In general, a picture signal has a very large quantity of information. In recording or transmitting a picture signal, a method for reducing quantity of information included in the picture signal with a high-efficiency coding without deteriorating picture quality for a visual sensation has been employed. For example, an encoding apparatus of a prior art uses an orthogonal transformation method as shown in FIG. 14 illustrating a block diagram showing configuration. In FIG. 14, numeral 1 designates an input terminal, 2 a blocking unit, 3 an orthogonal transformer, 4 an encoder and 5 an output terminal. The encoding apparatus, at first, puts an input signal inputted from the terminal 1 into blocks of a predetermined size by the blocking unit 2. Then, the encoding apparatus orthogonally transforms each block by the orthogonal transformer 3 and encodes the blocked input signal by the encoder 4. The quantity of data after encoding is predetermined. Therefore, the encoder 5 controls encoding so that the quantity of data after the encoding becomes not larger than the predetermined quantity. For example, the encoder 5 controls to gather m blocks of signals and to encode them so that the quantity of the encoded data is always kept under a predetermined data quantity x.
The above-described prior-art structure, however, has the following problem. When signals of different formats are inputted, such as picture signals of 4:3 and 16:9 for the horizontal to vertical screen frame ratio and high-definition picture signals having a wide frequency range, these signals should be processed with individually different coding data formats. Accordingly, encoded data corresponding to picture signals of different formats can only be decoded by individual decoders respectively.